Christian Sonderegger makes his feature debut with the film.

“This is Jacob. It is July 3, 2010, and I am one day on testosterone.” So begins the trailer for Christian Sonderegger’s documentary “Coby,” which premieres at Cannes this weekend and follows a 23-year-old who changes gender. Watch said trailer, which has been shared exclusively with IndieWire, below.

Here’s the synopsis: “A small town smack bang in the American Midwest. Suzanna, aged 23, changes gender and becomes a boy: Coby. her transformation deeply disrupts the lives of all who love her. Ultimately, Coby’s chrysalis morphs into the transformation of a whole family compelled to modify their own perspectives. not only a physical metamorphosis is at stake here, but also a spiritual one that eventually takes place under the director’s bright, unusual eye.”